The flu vaccine: What you need to know

The National Health Service has warned it could run out of stocks of flu vaccine this winter amidst public alarm about bird flu - despite the fact that the jab will not protect against a pandemic strain. Here we answer some frequently asked questions about the annual flu jab:

Why is the annual flu jab offered in the first place?

In most years, it is estimated that several thousand deaths are attributable to the complications of flu and around 10 per cent to 15 per cent of the population develop flu each year.

Flu is highly infectious - 100,000 flu particles can be projected into the air with one sneeze, and in just 12 hours the flu virus can invade one million nose and throat cells.

Who is eligible for the flu jab?

Over-65s and people with diabetes and chronic respiratory conditions, such as asthma.

People with serious heart or kidney disease, or people undergoing cancer treatment are also eligible.

Parents with children aged over six months with asthma or diabetes or weakened immunity due to disease or treatment are also being encouraged to bring them into GP surgeries for a free jab.

Other groups include residents in long-stay care homes and people who have lowered immunity due to HIV or are on steroid medication.

NHS workers are also urged to get a free flu jab in order to protect patients.

Why isn't the flu vaccine recommended for everyone?

Flu is not normally life-threatening for healthy people, and the occasional bout of flu gives better long-term protection than a flu vaccination.

Immunising everyone would not represent the "best use of current resources", according to the Department of Health website.

Can the annual flu jab act as a protection against bird flu?

The jab is unlikely to offer any protection at all against a pandemic strain of flu which has emerged from a mutation of bird flu.

Why is there a shortage of vaccine?

The recent scare over avian flu has led more people to seek vaccination this year from their GPs in spite of warnings that the annual flu jab will be no protection.

Dr David Salisbury, the Department of Health's head of immunisation, has said there is concern that the flu jab has been used on the "worried well" rather than the pre-agreed risk groups and this has contributed to the shortfall.

The British Medical Association disputes this claim, saying there is no evidence to support the claim that GPs have been using the the vaccine inappropriately.

Last year 71 per cent of over-65s took up the offer of the annual flu jab. The figure is expected to be considerably higher this winter.

How much vaccine had been ordered for this year?

Dr Salisbury has said the Department of Health met manufacturers to ensure that enough vaccine was available for the 11 million people in the groups recommended to receive the jab.

He said a record 14 million doses were available this year - far more than is required - but all of these doses have now been delivered to GPs or are in the process of being delivered.

The Department of Health has attempted to ease the pressure by issuing stock from its contingency reserve but it is expected that this will be exhausted soon.

A further contingency stock of 200,000 doses has been ordered to be delivered by late January, and the Department of Health is working to secure additional vaccine but it has said it might not be successful because of increased international demand.

Has there been a shortage of vaccine before?

There were problems with supply last year after the jab maker Chiron had its licence to make the vaccine suspended over concerns about the manufacturing process.